contain 4 AWG or larger insulated circuit conductors, and these conductors enter a cabinet
, a box, an enclosure
, or a raceway
, the conductors shall be protected by an identified fitting
providing a smoothly rounded insulating surface, unless the conductors are separated from the fitting
insulating material that is securely fastened in place
Exception: Where threaded hubs or bosses that are an integral part of a cabinet, box, enclosure, or raceway provide a smoothly rounded or flared entry for conductors.
Conduit bushings constructed wholly of insulating material shall not be used to secure a fitting or raceway. The insulating fitting or insulating material shall have a temperature rating not less than the insulation temperature rating of the installed conductors.